That "aircraft full of flight recorders" joke reminds me of another one. On the news. the reporter says: "A small, 4 seater, Cessna crashed in a cemetery today. Rescue teams recovered 98 bodies so far, and the numbers is still rising."
I laughed way harder than I should have at the bit about an aircraft full of flight recorders crashing. :) I love your teardown videos. I haven't got the foggiest idea what most of the bits that make up these things are (or what the do), but it is still cool to see them inside of items people encounter.
Oh and in addition, during a crash, the motor will stop running. So no damage can come to the tape from winding, provided the padding around the tape does its job.
Late 80s-early 90s I think. Stuff like this has lengthy approvals processes so you want to keep a design in produciton for as long as possible. Beacon will probably have been replaced since the recorder was new.
Data cartridges record continuously in alternate directions - the 4-head setup suggests this is probably the case for this unit, so it can record and verify in both directions.
Great teardown! I've been wanting one of these for years, but now that I know whats inside them, I guess I'll use something more commonly available as a door stopper :)
Well, this is probably about 6 years too late, but anyway... The reason the upper connector on the rear panel isn't populated is that that specific unit only has the basic (6 parameter) DAS card in it. There were 5 basic variants of this model, indicated by the first letter of the part number suffix (D = Digital only, needs external FDAU / E = Extended DAS, supports 10 parameters (UK CAA spec) / F = Basic DAS, supports 6 parameters / G = Extended DAS, supports 11 parameters (US FAA spec) / H = Shipped in E configuration but can be expanded to G by installing the extended DAS card) The config code is on the end of the part number - in your case FWUS - so F = Basic DAS / W = Pitot/Static with Wiggins connectors / U = ULB Installed at shipment / S = Standard case. The BITE LED on the front panel is indeed Built In Test Equipment - this unit also had a (for the time) advanced feature where every time it wrote a block on the tape it then wound the tape back and verified it, so it could detect write failures in normal operation. The connector on the front panel is for dumping the data - either directly to a system (based on a Data General Nova 4!) called ADRAS or indirectly using a copy recorder that dumped the internal data onto 1/4" reel-to-reel tape. Very slowly.
Flash is much more resistant to high temps than tape - if damage is so severe it can mechanically damage the tape it won't be in any shape to splice together. Flash could also distribute redundant data over multiple chips or boards easily.
I suspect these may have been the result of early CAD. Right-angle traces aren't a big deal, but have more inductance and can have manufacturing issues at finer line widths
Having worked for Honeywell in the avionics division, in IT though not directly with avionics, I can say that you will see lots of avionics with bodgery on them. A lot of the lines aren't high volume, and even the ones that are, anything that's rejected from QC inspection goes through a "rework station" where they replace whatever components that have failed without having to try and remake the PCB.
If you ever do pick one of these up to play with, especially older units with tapes, be quite careful. I was warned by a lawyer for a former employee of one manufacturer of these that they may contain asbestos as fireproofing material. The electronics are generally quite safe, but the tape side (which is usually its own compartment) is where the danger may lie.
Brilliant! The tape drive motor is probably external because it is dissipating a small but non-trivial amount of heat. Inside the insulated compartment, this would build up, reducing the recorder's time-temperature rating.
Unless I'm mistaken, the majority of FDR manufacturers have facilities very near the airplane factories, also the chips on the pcb's turn a different color if a temperature is exceeded for a particular time, that tells the techs that the data is probably corrupt. There still are lots of tape recorders flying as well as the older style foil type, as well as the newer flash type, but with ever increasing number of planes with sat links, some of them are flowing data directly to the airlines.
The best way to de-pot stuff I found is to just use a dremel with a wire brush attachment. It will eat right through the rubber, but leave components and the PCB intact.
The flight recorder shipments are probably arranged to use a different brand of flight recorder or maybe have it or the ones being shipped out specially marked or designated somehow.
The latest trend in flight recorders is the deployable type. They are much cheaper to manufacture because they don't have to be as well protected as a permanently mounted one- they are designed to be deployed from the aircraft before they go down. This also increases the likelihood of the recorder actually being found.
22:00 The extra wires going to the pressure sensor are likely for temperature compensation. Some of the EEPROMs are likely programmed with the compensation values. (Horner's Meathod data)
When does the engineers learn not to put on a "Do not open" label on equipment that should not be opened. Put a "Instructions inside" label instead. Great (and a little morbid) start to the video.
another reason for the motor to be outside: the belt is more likely to break, making it easier get the tape to stop during impact, making it easier for investigators to find the start/end of the loop
+SkyCharger001 I was thinking it'd break once enough heat was created and to ensure it to stop recording. Just because you want circuitry to stop at a certain time, doesn't mean it always will -- think about that after 300gs or its underwater.
+BikingMNViking: A. I never said it was a certainty, just that it's more likely. B. with flight-recorders of this kind the tape should be long enough for the difference between end-point and stopping-point to be relatively insignificant (IE: investigators only need to check 1/16th of the tape for the end/start-point instead of the entirety of it)
SkyCharger001 When does thing turn on? All I was trying to point out is that you would want it to shut off in a catastrphic fire and having the belt exposed to the heat would ensure that. The belt might have a specific temp at which it fails.
Probably, I've never googled any more details about how they work. I would just think one would want the most usage of the tape and after everyone is either too far from the mic to be heard over the roar of the fire or that everyone left near the recorder is dead so it'd be advantageous to have the belt melt off since there is obviously no reason to have it left running at this time. Without knowing what starts it up it may even be an overall event timing device -- I mean it can not record pitot tube data forever (today's new digital ones probably could and just loop over itself own memory) and I know that has been VERY helpful in some crashes -- one recently had the plane's pitot tube ice over and the autopilot pushed the power to max to try to increase airspeed which of course only iced up the pitot tube even more. The result was everyone died. I wish I could remember the flight number but what surprised me about it was that it was quite a modern aircraft but it was flying near some mountains as I recall. Interesting also to note during his gyro teardowns the bearings are nothing fancier than what is in my bicycle rather it is the devil in the details. They take plenty of care to balance the unit. (interesting balancing vid from Suburban Tool where they take a tour of remanufacturing a spool -- THEY even call in an expert to rebalance CNC mill heads that spin over 25k!) I'm sure they use wide-temp spec grease, too, because you loose 2 degrees F every 1k ft you are away from Earth. Aircraft have some of the best designing & engineering ever done on Earth, that's for sure. Lives in the balance.
I wouldn't be surprised if Dukane actually manufactured the transducer itself; they are a world leader in acoustic manufacturing technologies and one of the few makers of ultrasonic welders who makes their horns entirely in house, including the ceramics.
Great teardown Mike - Have you considered doing some more videos on military grade equipment? I found your previous teardown on those random military boards really informative as to how much work goes into the development of high spec hardware.
Honeywell has a number of solid state FDR's on their website. They appear to be the same size externally (compatibility/integration?) but I assume the internal electronics are going to be smaller.
Oh, does it rewind the tape when it's done? That will case some data loss. But I guess recording "backwards" wouldn't work since it would keep the old data and overwrite what just happened before the tape ended.
This device is exactly what records data from the control systems and sensors on the plane. Why would it have pressure inputs and whatnot if it didn't? The voice recorder is usually a separate device, and in fact, data recorders came first.
A good point. Especially if all of the flight recorders have that underwater beacon fully operational... Good luck trying to find one needle of a stack of needles, that make a hell of a lot of noise...
Yes, it is very VERY expensive to certify hardware for aviation, especially for commercial aviation. It's far far cheaper to stay with slightly older hardware than to replace it.
It seems a bit strange that they would use flash. If it gets damaged everything is lost. If the tape gets damaged you can splice together the good parts and still get data from it.
Okay I'm 44 seconds into the video and really want to know where you got that and if you know where I can locate some obsolute/surplus aircraft gear and instruments? Cheers!
The latest thought is that they should start moving to continuous data streaming from aircraft to land based recording facilities via some kind of TDRSS satellite link. I like the idea. No more worrying about recovering a data recorder in 8,000 feet of water in a Air France 447 type scenario anymore. Physical data recorders aboard the aircraft can be used as backups.
How old was this thing? The AMD chips on there were really old tech.. but the expiry on the beacon was 2005 I think.. does the beacon have a really long life or is it older tech for a reason?
Excellent teardown, as usual. Very interesting to see. I was quite surprised to see all those bodge wires considering the rest of the design. Also, I wonder what keeps fire from entering through the slot for the belt and destroying the tape.
[sic] not military looks like ARINC 747 compliant FDR. Military grade parts just means environmentally resistant Real military grad would mean no FDR / shitty sd card in a palm pilot / ipod plugged USB into the cockpit
I've depopulated a few conformal-coated PCBs in my time; it can be quite a challenge if you don't have a desoldering pump (I can't afford one!). The worst I've ever worked with was an ECU for a Nissan VG30DE V6 engine- I only managed to salvage a handful of components off of it because of the sheer thickness of the coating...
Problem is it's hard to get interesting stuff at a decent price. Won an aircraft laser on ebay a while ago but the Ministry of Defence stepped in & stopped the seller shipping it. Bastards.
Problem with salt water is that it absorbs quite a bit of radio energy and passive RFID technology is range restrictive. This is probably why it uses a transducer to send the locating pings instead of a radio ping. Now, your idea isn't that far fetch though, because for people who ski, I recall that they do use a form of RFID beacon to location people in the event of an avalanche.
Any clue about what type of data gets recorded on that device? Might be interesting to trace out the pinout of some of the input ports and see what types of things the flight recorder actually records. I wondered if what gets recorded is analog or digital. Also, what type of equipment is needed to read such as recorder? A computer? Dedicated device? An insturment panel? Other?
That 8080 chip is a bit of a surprise, to me anyway. The Intel 8080 was made in 1974 I think and then however long it took AMD to reverse engineer it from there (it wasn't licenses at first). It's a surprise because it was still one the market as one of the more advanced chips in 1977.
Perhaps putting the motor inside the heat-proof case would cause the tape temperature to rise too much if the motor gives off a fair bit of heat? Other than that, size is probably the only other reason.
That "aircraft full of flight recorders" joke reminds me of another one.
On the news. the reporter says: "A small, 4 seater, Cessna crashed in a cemetery today. Rescue teams recovered 98 bodies so far, and the numbers is still rising."
+Cristi Neagu
local caretaker: "are ya daft? all those desecrated graves!" ;)
I laughed way harder than I should have at the bit about an aircraft full of flight recorders crashing.
:)
I love your teardown videos. I haven't got the foggiest idea what most of the bits that make up these things are (or what the do), but it is still cool to see them inside of items people encounter.
Oh and in addition, during a crash, the motor will stop running. So no damage can come to the tape from winding, provided the padding around the tape does its job.
Late 80s-early 90s I think. Stuff like this has lengthy approvals processes so you want to keep a design in produciton for as long as possible. Beacon will probably have been replaced since the recorder was new.
I'm sure there are probably plenty of tape recorders flying, but new recorders will obviously be using flash memory.
Data cartridges record continuously in alternate directions - the 4-head setup suggests this is probably the case for this unit, so it can record and verify in both directions.
Great teardown! I've been wanting one of these for years, but now that I know whats inside them, I guess I'll use something more commonly available as a door stopper :)
Well, this is probably about 6 years too late, but anyway... The reason the upper connector on the rear panel isn't populated is that that specific unit only has the basic (6 parameter) DAS card in it. There were 5 basic variants of this model, indicated by the first letter of the part number suffix (D = Digital only, needs external FDAU / E = Extended DAS, supports 10 parameters (UK CAA spec) / F = Basic DAS, supports 6 parameters / G = Extended DAS, supports 11 parameters (US FAA spec) / H = Shipped in E configuration but can be expanded to G by installing the extended DAS card)
The config code is on the end of the part number - in your case FWUS - so F = Basic DAS / W = Pitot/Static with Wiggins connectors / U = ULB Installed at shipment / S = Standard case. The BITE LED on the front panel is indeed Built In Test Equipment - this unit also had a (for the time) advanced feature where every time it wrote a block on the tape it then wound the tape back and verified it, so it could detect write failures in normal operation.
The connector on the front panel is for dumping the data - either directly to a system (based on a Data General Nova 4!) called ADRAS or indirectly using a copy recorder that dumped the internal data onto 1/4" reel-to-reel tape. Very slowly.
Awesome information!
Lol loved the intro.
Love the intro :D
You find the most unusual things to delve into Mike :D
a complete one would make a great ornament in a workshop or living room :D
Flash is much more resistant to high temps than tape - if damage is so severe it can mechanically damage the tape it won't be in any shape to splice together. Flash could also distribute redundant data over multiple chips or boards easily.
I suspect these may have been the result of early CAD. Right-angle traces aren't a big deal, but have more inductance and can have manufacturing issues at finer line widths
Having worked for Honeywell in the avionics division, in IT though not directly with avionics, I can say that you will see lots of avionics with bodgery on them. A lot of the lines aren't high volume, and even the ones that are, anything that's rejected from QC inspection goes through a "rework station" where they replace whatever components that have failed without having to try and remake the PCB.
If you ever do pick one of these up to play with, especially older units with tapes, be quite careful. I was warned by a lawyer for a former employee of one manufacturer of these that they may contain asbestos as fireproofing material. The electronics are generally quite safe, but the tape side (which is usually its own compartment) is where the danger may lie.
Brilliant! The tape drive motor is probably external because it is dissipating a small but non-trivial amount of heat. Inside the insulated compartment, this would build up, reducing the recorder's time-temperature rating.
"OMG 700 planes have just gone down in the same spot!"
Fascinating stuff. Not something you get to see inside of everyday. Love the end thought.
Unless I'm mistaken, the majority of FDR manufacturers have facilities very near the airplane factories, also the chips on the pcb's turn a different color if a temperature is exceeded for a particular time, that tells the techs that the data is probably corrupt. There still are lots of tape recorders flying as well as the older style foil type, as well as the newer flash type, but with ever increasing number of planes with sat links, some of them are flowing data directly to the airlines.
The best way to de-pot stuff I found is to just use a dremel with a wire brush attachment. It will eat right through the rubber, but leave components and the PCB intact.
Thanks!
The flight recorder shipments are probably arranged to use a different brand of flight recorder or maybe have it or the ones being shipped out specially marked or designated somehow.
Thank you, sir. Excellent job of describing the components. I appreciate your sense of humor and your technical acumen. Cheers.
The latest trend in flight recorders is the deployable type. They are much cheaper to manufacture because they don't have to be as well protected as a permanently mounted one- they are designed to be deployed from the aircraft before they go down. This also increases the likelihood of the recorder actually being found.
Fascinating to see. I love the looks of military and similar spec electronics, the quality is so good, and is pleasing to the eye.
where did you got a flight data recorder ?
Older ones use metal foil to record mechanical traces on - there is a teardown of one of these online somewhere
Did everyone watch this twice ! Great tear down Mike as usual.
only twice ? lol
can you show this video to the inspectors of the MH17 flight recorder? I guess they have still trouble opening it...................
TheThore haha true !
in that hole there is probably a piece of intumescent material that expands significantly when it gets hot, sealing that hole up.
22:00 The extra wires going to the pressure sensor are likely for temperature compensation. Some of the EEPROMs are likely programmed with the compensation values. (Horner's Meathod data)
When does the engineers learn not to put on a "Do not open" label on equipment that should not be opened. Put a "Instructions inside" label instead.
Great (and a little morbid) start to the video.
It's really cool just to see what these things are really made of, and gives a bit of insight to how they work as well.
another reason for the motor to be outside: the belt is more likely to break, making it easier get the tape to stop during impact, making it easier for investigators to find the start/end of the loop
+SkyCharger001 I was thinking it'd break once enough heat was created and to ensure it to stop recording. Just because you want circuitry to stop at a certain time, doesn't mean it always will -- think about that after 300gs or its underwater.
+BikingMNViking: A. I never said it was a certainty, just that it's more likely. B. with flight-recorders of this kind the tape should be long enough for the difference between end-point and stopping-point to be relatively insignificant (IE: investigators only need to check 1/16th of the tape for the end/start-point instead of the entirety of it)
SkyCharger001
When does thing turn on? All I was trying to point out is that you would want it to shut off in a catastrphic fire and having the belt exposed to the heat would ensure that. The belt might have a specific temp at which it fails.
+BikingMNViking : perhaps it's easiest to say that a Flight-Recorder has multiple deliberate failure-modes.
Probably, I've never googled any more details about how they work. I would just think one would want the most usage of the tape and after everyone is either too far from the mic to be heard over the roar of the fire or that everyone left near the recorder is dead so it'd be advantageous to have the belt melt off since there is obviously no reason to have it left running at this time.
Without knowing what starts it up it may even be an overall event timing device -- I mean it can not record pitot tube data forever (today's new digital ones probably could and just loop over itself own memory) and I know that has been VERY helpful in some crashes -- one recently had the plane's pitot tube ice over and the autopilot pushed the power to max to try to increase airspeed which of course only iced up the pitot tube even more. The result was everyone died. I wish I could remember the flight number but what surprised me about it was that it was quite a modern aircraft but it was flying near some mountains as I recall.
Interesting also to note during his gyro teardowns the bearings are nothing fancier than what is in my bicycle rather it is the devil in the details. They take plenty of care to balance the unit. (interesting balancing vid from Suburban Tool where they take a tour of remanufacturing a spool -- THEY even call in an expert to rebalance CNC mill heads that spin over 25k!) I'm sure they use wide-temp spec grease, too, because you loose 2 degrees F every 1k ft you are away from Earth. Aircraft have some of the best designing & engineering ever done on Earth, that's for sure. Lives in the balance.
Your a very smart person, youtube should be paying you for your input. Well done
I wouldn't be surprised if Dukane actually manufactured the transducer itself; they are a world leader in acoustic manufacturing technologies and one of the few makers of ultrasonic welders who makes their horns entirely in house, including the ceramics.
great dramatic beginning ... bravo ! nice shiney chipsets
not sure how i stumbled on your video, but this is a very interesting channel you have here. keep up the good work!
I think it records in alternate directions, one track at a time
Fascinating to see inside, even if I know nothing about electronics.
Great teardown Mike - Have you considered doing some more videos on military grade equipment? I found your previous teardown on those random military boards really informative as to how much work goes into the development of high spec hardware.
Nice video! How do you get your hand on this stuff?
AWESOME video mate!!!! Where did you manage to find one of those beauties??? :)
Did I get the date code right on one of the IC's of the PCB stack inside: 25th week of 87? (seen at 11:34)
Honeywell has a number of solid state FDR's on their website. They appear to be the same size externally (compatibility/integration?) but I assume the internal electronics are going to be smaller.
Oh, does it rewind the tape when it's done? That will case some data loss. But I guess recording "backwards" wouldn't work since it would keep the old data and overwrite what just happened before the tape ended.
This device is exactly what records data from the control systems and sensors on the plane. Why would it have pressure inputs and whatnot if it didn't? The voice recorder is usually a separate device, and in fact, data recorders came first.
Have you ever come across the really old steel wire recorders?
always very interesting to watch your teardown videos. loved the beginning and ending.
A good point. Especially if all of the flight recorders have that underwater beacon fully operational...
Good luck trying to find one needle of a stack of needles, that make a hell of a lot of noise...
Yes, it is very VERY expensive to certify hardware for aviation, especially for commercial aviation. It's far far cheaper to stay with slightly older hardware than to replace it.
i wonder if you could locate another wheel that the reel-to-reel could possibly be reused for audio?
This is a great video. Thanks for sharing. Did you notice many "TAIWAN" markings at 14:37?
It seems a bit strange that they would use flash. If it gets damaged everything is lost. If the tape gets damaged you can splice together the good parts and still get data from it.
Okay I'm 44 seconds into the video and really want to know where you got that and if you know where I can locate some obsolute/surplus aircraft gear and instruments? Cheers!
same place the rest of us get it , EBAY
Don't be a smartassel
I really enjoy your videos! I'm glad i found your channel.
I recommend this video for anybody who thinks himself/ herself as engineer. Thanks for the video.
The latest thought is that they should start moving to continuous data streaming from aircraft to land based recording facilities via some kind of TDRSS satellite link. I like the idea. No more worrying about recovering a data recorder in 8,000 feet of water in a Air France 447 type scenario anymore. Physical data recorders aboard the aircraft can be used as backups.
I wonder how long it takes to rewind? What happens if there is a flight problem while it is rewinding?
How old was this thing? The AMD chips on there were really old tech.. but the expiry on the beacon was 2005 I think.. does the beacon have a really long life or is it older tech for a reason?
how would that ping help someone find it if you have to be so close to it to actually hear it with the transducer?
Excellent teardown, as usual. Very interesting to see. I was quite surprised to see all those bodge wires considering the rest of the design. Also, I wonder what keeps fire from entering through the slot for the belt and destroying the tape.
What are those lil round components like LED soldered flush to the board surface, they sorta clear sea through LED type things?
I would guess that the motor is outside the case because the motor itself is a potential fire risk?
Were the boards coated in varnish?
How do you get your hands on one of these? And how expensive is it?
That makes sense, seeing as you could store so much more information.
All this military grade stuff is so pretty.
[sic] not military looks like ARINC 747 compliant FDR.
Military grade parts just means environmentally resistant
Real military grad would mean no FDR / shitty sd card in a palm pilot / ipod plugged USB into the cockpit
Is that fluffy looking material behind the yellow shell asbestos?
I've depopulated a few conformal-coated PCBs in my time; it can be quite a challenge if you don't have a desoldering pump (I can't afford one!). The worst I've ever worked with was an ECU for a Nissan VG30DE V6 engine- I only managed to salvage a handful of components off of it because of the sheer thickness of the coating...
Those are the most beautiful circuit boards I have ever seen
Those first 2 pcbs you pulled out had right angle corners on the pcbs traces. I thought that was a big no-no.
Very interesting, but you should have really been helping outside with the airplane crash....nice scope too, I'm still on cathode ray!!
Do they still use tapes today?
Great teardown!!!
I liked the beginning and ending....Hell I loved all of it!!
Problem is it's hard to get interesting stuff at a decent price. Won an aircraft laser on ebay a while ago but the Ministry of Defence stepped in & stopped the seller shipping it. Bastards.
How the hell did you get a full flight data recorder? Are you a manufacture of flight data recorders?
Ebay lol
Motor outside the fireproof case to isolate tapes from magntic field?
The automatic captions are very useful! How do they do it?
This is one of my favorite shows on you tube!
What kind of battery was that? Lithium Sulfate?
That's highly impressive for 6 layers, when was it made?
Problem with salt water is that it absorbs quite a bit of radio energy and passive RFID technology is range restrictive. This is probably why it uses a transducer to send the locating pings instead of a radio ping. Now, your idea isn't that far fetch though, because for people who ski, I recall that they do use a form of RFID beacon to location people in the event of an avalanche.
The outer layer doesn't look all too rugged? Surprised it doesn't get destroyed when dropped from 30,000ft!
Excellent, this is the way to learn things! Keep them coming!
I can just imagine the investigation team looking through a hundred flight recorders trying to find the one that has the data!
Where the heck do you get this stuff? :O
I heard somewhere that having one of these is actually illegal, is that true?
Any clue about what type of data gets recorded on that device? Might be interesting to trace out the pinout of some of the input ports and see what types of things the flight recorder actually records. I wondered if what gets recorded is analog or digital. Also, what type of equipment is needed to read such as recorder? A computer? Dedicated device? An insturment panel? Other?
as salt water is not shorted the beacon if you can measure the voltage of the battery through the case?
Can you put the heat enclosure in an oven to see how slowly the temperature rises inside ? Would be interesting.
I always love opening up stuff that says "DO NOT OPEN!"
How does the magnetic read/write head work?
Any training available?
where did you get that?? I want one
That 8080 chip is a bit of a surprise, to me anyway. The Intel 8080 was made in 1974 I think and then however long it took AMD to reverse engineer it from there (it wasn't licenses at first). It's a surprise because it was still one the market as one of the more advanced chips in 1977.
What do you use for hex editor?
interesting. I figured it would be like a computer hard drive. wonder if the new ones are like SSD based. think be a lot less sensitive to shock, etc.
The last pressure sensor is a automotive type manifold pressure sensor.
Perhaps putting the motor inside the heat-proof case would cause the tape temperature to rise too much if the motor gives off a fair bit of heat? Other than that, size is probably the only other reason.
Where can I buy old flight recorders like this, and how much do they cost?
Love the sound of that fire in the intro. Reminds me of Half Life 1 🎮